The market tension centers on the massive borrowing required to fund rapid data-center expansion. CoreWeave shares experienced sharp swings, closing up 1.7% to $62.13 after falling more than 6% earlier in the day. Analysts point to the firm as a bellwether for the sector, where high interest rates threaten to squeeze margins for companies relying on heavy financing. The scale of this investment is immense; recent disclosures suggest Anthropic may spend $750 billion on computing capacity in the coming years, a figure that would eclipse any other infrastructure investment in American history.

Economic headwinds further complicated the sentiment. Housing starts dropped 5.2% in September, with pending sales hitting their lowest point since 2001 as mortgage rates remain elevated. Meanwhile, the corporate landscape showed a sharp divergence in performance. 3M shares climbed 5.8% after raising its full-year outlook, while General Motors shares fell 6.8% under the pressure of rising logistics and commodity costs. In the aerospace sector, Northrop Grumman rose 4.6% as CEO Kathy Warden cited a multi-year upswing in global defense budgets, providing a rare pocket of stability amid the day's mixed results.